The object of this project is to examine the regulation of gene expression in neoplasms as well as during the normal growth and differentiation process. Our aim is to identify and characterize both cellular and genetic factors that are of critical importance in the oncogenic process. The experimental systems presently under study are: (1) a variety of undifferentiated human B cell lymphomas and human acute lymphocytic and myeloid leukemia; (2) the human promyelocytic leukemia cell line HL60; and (3) the rat hepatoma cell lines and primary hepatocytes. The results obtained and the experiments in progress in the human lymphoma/leukemia system includes (1) characterization of the transcriptional activity of c-mos and c-myc oncogenes in human B-cell lymphomas; (2) chemical transformation of lymphoblastoid cell lines; (3) further characterization of the role of EBV in human B-cell lymphomas; and (4) two-dimensional gel analysis of proteins associated with acute lyjmphocytic and myeloid leukemias using the NIH 3T3 transfection system. The results obtained and the experiments in progress in the HL60 cell line include: (1) delineation of c-myc RNA expression in growth or differentiation; (2) myristic acid regulation in the expression of differentiation specific proteins; and (3) two-dimensional gel analysis of HL60 whole cell proteins after chemically induced differentiation induced by 12-0-tetradecanoyl-phorbol-13-acetate (macrophage) or by dimethylformamide (granulocyte). The results obtained and the experiments in progress in the rat hepatoma and primary hepatocytes include: (1) partial construction of cDNA libraries using the expression vector system to trans-stilbene oxide induced rat liver, for the cloning and subsequent characterization of epoxide hydrolase as well as to partially hepatectomized rat livers for the cloning and subsequent characterization of genes associated with cellular proliferation in the liver; (2) characterization of changes in transcriptional levels of genes coding for differentiation specific mRNAs, specifically gamma-glutamyl-transpeptidase as well as alpha-fetoprotein and albumin genes after in vitro treatment of rat hepatoma cell lines with sodium butyrate and dexamethasone.